Nickel Alloy 718
UNS N07718 · EN 2.4668, NiCr19Fe19Nb5Mo3 · GB GH4169
718 (N07718, 2.4668, GH4169) is an age-hardenable Ni-Cr-Fe superalloy strengthened by Nb-driven γ″ precipitates, reaching 1170 MPa yield and 1375 MPa tensile strength with 18% elongation and 204 GPa modulus in the solution-treated and aged condition.
Reference datasheet — 718 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the STA condition
718 tempers and conditions
718 is supplied in 10 conditions, soft to hard. STA is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest supply condition for forming, deep drawing, machining or welding before final aging. | 500 | 965 | 45 | 200 HB | — |
Hot Finished | As-forged or hot-rolled bar bought for re-forging or for parts that will be solution treated and aged by the customer. | 640 | 1,050 | 35 | 24 HRC | 1.4 % IACS |
Additive as-built | Printed condition with columnar grains and Laves phase; adequate for prototypes but anisotropic and low in yield strength until heat treated. | 700 | 1,030 | 27 | 30 HRC | 1.3 % IACS |
As cast | Complex-geometry housings, casings and valve bodies; strength and ductility below wrought due to dendritic segregation and Laves phase. | 880 | 1,030 | 9 | 35 HRC | — |
Cold drawn | Straight, close-tolerance bar and wire with work-hardened strength; use when tight size and moderate strength are needed without aging. | 930 | 1,140 | 18 | 33 HRC | 1.4 % IACS |
STA | Coarser grain, slightly lower tensile but better creep-rupture life, notch ductility and fracture toughness for hot rotating parts. | 1,050 | 1,275 | 21 | 38 HRC | — |
Additive + HIP + homogenize/solution + double age (AMS 5662-equivalent) | Fully densified and homogenized printed parts reaching wrought-like strength; the standard route for flight and downhole AM 718 hardware. | 1,160 | 1,380 | 16 | 43 HRC | 1.4 % IACS |
STADefault Solution treated and aged | Default aerospace/oil-field condition: fine grain plus full γ″ hardening for maximum room- and mid-temperature strength. | 1,170 | 1,375 | 18 | 42 HRC | — |
Direct aged | Retains hot-work substructure for the highest tensile/LCF strength; used for turbine discs, fasteners and downhole tools where fine grain and strength dominate. | 1,250 | 1,450 | 15 | 45 HRC | — |
Cold worked + aged strip/wire | Cold-rolled or drawn then aged for springs, seals, bellows and fasteners needing the highest hardness in thin sections. | 1,350 | 1,520 | 10 | 47 HRC | 1.4 % IACS |
Supply forms, finishes and certifications
Ways 718 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
SHEET-STA | Sheet/plate STA | Supply form |
What is 718?
718 (N07718, 2.4668, GH4169) is an age-hardenable Ni-Cr-Fe superalloy strengthened by Nb-driven γ″ precipitates, reaching 1170 MPa yield and 1375 MPa tensile strength with 18% elongation and 204 GPa modulus in the solution-treated and aged condition. It combines that strength and creep resistance up to about 650 °C with the best weldability of the age-hardenable superalloys, and is available as bar, forgings, sheet, plate, castings and additively built parts. Machinability (15) and cold formability (15) are both poor, and δ-phase precipitation limits hot-working windows. Waspaloy or X-750 are used above 650 °C. 718 has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 68% of nickel alloy grades. It melts at 1,260°C (2,300 °F). 718 has a yield strength of 1,170 MPa (170 ksi) and a tensile strength of 1,375 MPa (199 ksi) — stronger than 98% of nickel alloy grades. Elongation at break is 18% and the elastic modulus is 204 GPa (29.6 Msi).
What is 718 used for?
- turbine disks
- aerospace fasteners
- gas turbine casings
- oil & gas downhole components
- cryogenic tanks
Advantages
- High strength — 1,170 MPa (170 ksi), better than 98% of nickel alloy grades
Limitations
- Limited formability — 15/100, worse than 81% of nickel alloy grades
- Limited ductility — 18%, worse than 77% of nickel alloy grades
718 properties
Typical room-temperature values for 718-STA; bars are the position among nickel alloy grades.
Physical3
718 has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 68% of nickel alloy grades. It melts at 1,260°C (2,300 °F).
Mechanical16
718 has a yield strength of 1,170 MPa (170 ksi) and a tensile strength of 1,375 MPa (199 ksi) — stronger than 98% of nickel alloy grades. Elongation at break is 18% and the elastic modulus is 204 GPa (29.6 Msi).
Thermal6
718 is rated for continuous service to 650°C (1,202 °F). It conducts heat at 11.4 W/m·K (6.59 BTU/hr·ft·°F), better than 53% of nickel alloy grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical3
718 conducts electricity at 1.4 % IACS, worse than 65% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 51% of nickel alloy grades.
Sustainability4
Producing a kilogram of 718 takes about 175 MJ of energy and emits 12.5 kg of CO₂ — more than 65% of nickel alloy grades. Typical recycled content is 40%.
Manufacturability8
718's machinability is poor (15/100, worse than 76% of nickel alloy grades); weldability good (65/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. 718 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 718
Is 718 easy to machine?
Machine in the annealed state where possible; when aged use rigid setups, low speeds (10–30 m/min carbide, 150–300 m/min ceramic), heavy positive feeds to cut under the work-hardened layer and high-pressure coolant.
Can 718 be welded?
Best weldability of the age-hardenable superalloys (GTAW/EBW/laser with ERNiFeCr-2 filler); weld in solution-annealed condition, keep interpass heat low and post-weld solution + double age to restore properties.
Can 718 be formed, bent or molded?
Cold form only in the annealed condition with high forces and frequent intermediate anneals; hot work at 1010–1120 °C and finish above ~950 °C to avoid δ-phase-driven cracking.
718 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| NiNi + Co | 50 – 55 | 53 |
| Cr | 17 – 21 | 19 |
| NbNb + Ta; γ″ former | 4.75 – 5.5 | 5.1 |
| Mo | 2.8 – 3.3 | 3 |
| Ti | 0.65 – 1.15 | 0.9 |
| Al | 0.2 – 0.8 | 0.5 |
| Co | ≤ 1 | 0.3 |
| C | ≤ 0.08 | 0.04 |
| Mn | ≤ 0.35 | 0.1 |
| Si | ≤ 0.35 | 0.1 |
| Cu | ≤ 0.3 | 0.05 |
| B | ≤ 0.01 | 0 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0 |
| Febalance, typically ~18.5 % | balance |
What surface finishes work on 718?
Grind/EDM with care for recast layer removal; shot peen critical fillets for fatigue, passivate or electropolish for corrosion service — no anodizing, plating and PVD coatings are used instead.
Surface treatments FabDigit runs on nickel alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy 718 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N07718
- EN / DIN / Werkstoff-Nr.
- 2.4668NiCr19Fe19Nb5Mo3
- GB (China)
- GH4169
- Other
- 5662
How much does 718 cost?
718 is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
718 — frequently asked
What is 718 used for?
718 is typically used for turbine disks, aerospace fasteners, gas turbine casings, oil & gas downhole components and cryogenic tanks. In short: best-weldable age-hardening superalloy; 1170 MPa yield when aged; workhorse turbine disk alloy.
What is the yield strength of 718?
718 has a typical yield strength of 1,170 MPa (170 ksi) and a tensile strength of 1,375 MPa (199 ksi) — stronger than 98% of nickel alloy grades. Strength varies by condition: see the 10 listed tempers.
Is 718 easy to machine?
Not especially — machinability is rated poor (15/100, worse than 76% of nickel alloy grades). Machine in the annealed state where possible; when aged use rigid setups, low speeds (10–30 m/min carbide, 150–300 m/min ceramic), heavy positive feeds to cut under the work-hardened layer and high-pressure coolant.
Can 718 be welded?
Yes — weldability is rated good (65/100). Best weldability of the age-hardenable superalloys (GTAW/EBW/laser with ERNiFeCr-2 filler); weld in solution-annealed condition, keep interpass heat low and post-weld solution + double age to restore properties.
What surface finishes work on 718?
Grind/EDM with care for recast layer removal; shot peen critical fillets for fatigue, passivate or electropolish for corrosion service — no anodizing, plating and PVD coatings are used instead.
Can 718 be formed, bent or molded?
Cold form only in the annealed condition with high forces and frequent intermediate anneals; hot work at 1010–1120 °C and finish above ~950 °C to avoid δ-phase-driven cracking.
What is the maximum service temperature of 718?
718 is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 718-STA and 718-ANN?
STA is the default condition — default aerospace/oil-field condition: fine grain plus full γ″ hardening for maximum room- and mid-temperature strength. ANN: softest supply condition for forming, deep drawing, machining or welding before final aging. Yield strength is 1,170 MPa in STA versus 500 MPa in ANN.
How much does 718 cost?
718 is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- INCONEL alloy 718 Technical Bulletin — Special Metals Corporation (2007)
- AMS 5662/5663/5664 — Nickel Alloy Bars, Forgings and Rings, 718 — SAE International (2020)
- ASTM B637 — Precipitation-Hardening Nickel Alloy Bars, Forgings and Forging Stock — ASTM International (2018)
- ASM Handbook Vol.1 & Vol.19 — Superalloys, Fatigue and Fracture — ASM International (1996)
- MMPDS-17 Nickel Alloy Design Allowables — Battelle/FAA (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.